Fluid applied silicone air and water barrier system and process thereof

Abstract

There is provided herein a one-part room temperature vulcanizing (RTV) silicone based air and water barrier composition comprising silanol-terminated diorganopolysiloxane polymer; fumed silica; stearic acid treated ground calcium carbonate extending filler; polyalkoxy crosslinking agent; metal chelate condensation cure catalyst; and, an adhesion promoter. There is also provided a wall assembly comprising said composition.

What is claimed is: 
     
       1. A wall assembly comprising a one-part room temperature vulcanizing (RTV) silicone based air and water barrier adhesive composition comprising:
 about 20 wt. % to about 80 wt. %, of silanol-terminated diorganopolysiloxane polymer having a viscosity between about 100 centipoise to about 500,000 centipoise at about 25 C.° wherein the organo groups are monovalent hydrocarbon radicals containing up to about 30 carbon atoms; 
 up to about 20 wt. % of a treated fumed silica reinforcing filler; 
 up to about 60 wt. % of at least one of a stearic acid treated ground calcium carbonate extending filler; and, a precipitated calcium carbonate filler; 
 about 0.5 wt. % to about 10 wt. % of a polyalkoxy crosslinking agent having the general formula:
   (R 1 O) 4-a —Si—R 2   a  
 
 
 
       where R 1  and R 2  are monovalent hydrocarbon radicals of up to about 30 carbon atoms, and a is zero, 1 or 2;
 about 0.05 wt. % to about 5 wt. % of a metal chelate condensation cure catalyst having the general formula: 
 
       
         
           
           
               
               
           
         
         where Me is a metal selected from the group consisting of lead, tin, zirconium, antimony, iron, cadmium, barium, manganese, zinc, cobalt, nickel, aluminum, gallium, germanium and titanium, 
         s is from about 0.7 to about 1.3, and t is from 1.2 to 0.8, 
         R 6  is a divalent hydrocarbon radical containing from about 2 to about 20 carbon atoms, optionally substituted with a hydrocarbon group containing up to 8 carbon atoms, 
         R 2  is hydrogen or an organic radical selected from the group consisting of hydrocarbyl, halohydrocarbyl and acyl each containing up to about 8 carbon atoms, 
         R 3  is hydrogen or an organic radical selected from the group consisting of hydrocarbyl, halohydrocarbyl and acyl containing up to about 8 carbon atoms, or R 3  is part of a cyclic hydrocarbon group formed by a bond to a carbon atom of the adjacent R 2  and/or R 3  group wherein the cyclic hydrocarbon group contains up to about 12 carbon atoms and is optionally substituted with one or more functional groups selected from the group consisting of chloro, nitro, ester, cyano, and carboxy ester substituents; 
         R 4  is defined the same as R 2 ; 
         R 5  is a monovalent organic radical selected from the group consisting of hydrocarbyl, halohydrocarbyl and ether containing up to 60 carbon atoms, cyanoalkyl containing up to 12 carbon atoms, amino, and polyether groups of the formula (C q H 2q O) v R 30 , where q is from 2 to 4, and v is from 1 to 20, and R 30  is a monovalent hydrocarbon radical of from 1 to 30 carbon atoms; 
         up to about 5 wt. % of an adhesion promoter selected from the group consisting of an organofunctional polyalkoxy silane adhesion promoter having the general formula: 
       
       
         
           
           
               
               
           
         
         where R 11  and R 12  are monovalent hydrocarbon radicals containing up to about 8 carbon atoms, 
         t is 0 to 3 and 
         Z is a saturated, unsaturated, or aromatic hydrocarbon containing up to about 30 carbon atoms, which is further functionalized by a group selected from the group consisting of ether, epoxy, isocyanato, cyano, acryloxy, and acyloxy; an isocyanato-functional polyalkoxy silane adhesion promoter of the general formula: 
       
       
         
           
           
               
               
           
         
         wherein G is selected from R 11  radicals as defined above, styryl, vinyl, allyl, chloroallyl, cyclohexenyl, and radicals of the formula 
       
       
         
           
           
               
               
           
         
         wherein R 11  and R 12  are monovalent hydrocarbon radicals containing up to about 8 carbon atoms, 
         where R 13  is a monovalent hydrocarbon radical containing up to about 8 carbon atoms or a monovalent cyanoalkyl radical containing up to 8 carbon atoms, and 
         wherein R 15  is a divalent hydrocarbon radical selected from the group consisting of alkylenearylene, alkylene, and cycloalkylene and halogenated alkylenearylene, alkylene, and cycloalkylene each containing from 2 to about 12 carbon atoms, and 
         where b is 0 or an integer from 1 to 2; and, combinations thereof; 
         an elastomer; and, 
         at least one substrate selected from the group consisting of a construction sheathing substrate, a metal substrate, a galvanized metal substrate and a wood framing substrate, wherein the adhesive bonds the elastomer to the substrate. 
       
     
     
       2. The composition of  claim 1  further comprising up to about 60 wt % of a hydrocarbon processing aid. 
     
     
       3. The composition of  claim 2  wherein the hydrocarbon processing aid, comprises greater than 40 weight percent cyclic paraffinic hydrocarbons and less than 60 weight percent noncyclic paraffinic hydrocarbons based on the total weight of the hydrocarbon processing aid. 
     
     
       4. The composition of  claim 3  wherein the cyclic paraffinic hydrocarbons are selected from the group consisting of cyclohexane, cyclooctane, cyclononane, and cyclododecane and combinations thereof. 
     
     
       5. The composition of  claim 3  wherein the non-cyclic paraffinic hydrocarbons are selected from the group consisting of n-heptane, n-octane, iso-octane, n-nonane, n-decane, n-undecane, n-dodecane, iso-decane, n-heptadecane, n-octadecane, n-eicosane, isoeicosane and combinations thereof. 
     
     
       6. The composition of  claim 1  wherein the silanol-terminated diorganopolysiloxane polymer is of the general formula: 
       
         
           
           
               
               
           
         
         where R 1  and R 2  are monovalent hydrocarbon radicals containing up to about 12 carbon atoms, and where “p” varies such that the viscosity of the polymer varies from about 100 centipoise to about 500,000 centipoise at 25 C.°. 
       
     
     
       7. The composition of  claim 1  wherein p is from 10 to about 4000. 
     
     
       8. The composition of  claim 1  wherein the polyalkoxy silane crosslinking agent is selected from the group consisting of methyltrimethoxysilane, vinyltrimethoxysilane, tetramethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane and tetraethoxysilane. 
     
     
       9. The composition of  claim 1  wherein Me is titanium. 
     
     
       10. The composition of  claim 1  wherein R 6  is propylene, R 3  is hydrogen, R 2  and R 4  are methyl and R 5  is ethyl. 
     
     
       11. The composition of  claim 1  wherein the metal chelate condensation catalyst is of the general formula: 
       
         
           
           
               
               
           
         
         wherein Ti is titanium and s and t are each 1. 
       
     
     
       12. The composition of  claim 1  wherein the adhesion promoter is selected from the group consisting of 1,3,5-tristrimethoxysilylpropylisocyanurate, bis-1,3-trimethoxysilylpropylisocyanurate, 1,3,5-tristrimethoxysilylethylisocyanurate, 1,3,5-trismethyldimethoxysilylpropylisocyanurate, 1,3,5-trismethyldiethoxysilylpropylisocyanurate, n-2-aminoethyl-3-aminopropyltriethoxysilane, methacryloxypropyltrimethoxysilane, methylaminopropyltrimethoxysilane, γ-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxyethyltrimethoxysilane, β-(3,4-epoxycyclohexyl)propyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethylmethyldimethoxysilane, isocyanatopropyltriethoxysilane, isocyanatopropylmethyldimethoxysilane, β-cyanoethyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, 4-amino-3,3,-dimethylbutyltrimethoxysilane, n-ethyl-3-trimethoxysilyl-2-methylpropanamine, and combinations thereof. 
     
     
       13. The composition of  claim 1  wherein the adhesion promoter is 1,3,5-tristrimethoxysilylpropylisocyanurate. 
     
     
       14. The composition of  claim 1  further comprising at least one of a flame retardant, a fungicide, a pigment and a colorant.